I have a unfinished, working, Late 1920's Ball Top GE Refrigerator and would like to post it on CL, but have no idea what these go for.
Look on ebay, and look at vintage appliance sites. Vintage appliance places sell both fully refurbished and unrefurbished pieces that you can buy and have them refurbished a certain way.
I would list yours at at least 50% less than what a retail unfinished unit is going for. On CL people are looking for bargains.